Team Members:
Kyle Bloomer
Josh Geiman
Lucas Bennett
Team Sponsor:
Dr. Cindy Harnett
Team Mentor:
Dr. Andy Dozier
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Dr. Harnett's laboratory needs 15 potentiostats for her
microfluidics lab
Off the shelf potentiostats range in price from $5K to
$10K, which is prohibitive for an instructional lab
Commercial Potentiostat
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A Potentiostat is the electronic hardware required to
control a three electrode cell and run most electroanalytical experiments.
An electronic instrument that controls the voltage
difference between a Working Electrode and a Reference
Electrode.
It measures the current flow between the Working and
Counter Electrodes.
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A previous potentiostat was attempted by a project team
using an open source design, the Ardustat
Hardware used was an Arduino processor board, with a
prototype “daughter board”
The Ardustat was a two electrode configuration
Ardustat electrical design was poorly documented,
which caused the project team to have difficulty
implementing it for the project
Software design had no documentation or comments for
either the firmware or the application software
The team was unable to meet the project goals
Before Ben
After Ben
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We have found an open source, three
electrode potentiostat, known as the
“Cheapstat”
Cheapstat was developed by UC Santa
Barbara to provide an affordable
alternative to COTS potentiostats
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Input parameters must be set through an
onboard LCD and 5-way joystick
The display is very limited
◦ LCD on the Cheapstat processor “box”
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Provides multiple measurement modes
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Square Wave
Linear Sweep
Stripping
Cyclic Voltammetry
Front Panel
PCB Assembly
Joystick
To Cell
Electrodes
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Two Electrode Potentiostat (Formally known as
the “Ardustat”)
Three Electrode Potentiostat (Formally known as
the “Cheapstat”)
Our project will entail the completion of both
systems and comparison of test results of both
systems.
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Characterize electrical performance for a typical
electrochemical device
Compare electrical measurements between the
two systems
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Two electrode vs. three electrode measurement
differences
Document all materials
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Design and implement a three electrode
potentiostat, based on the Cheapstat
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Ease of assembly and use by students, faculty,
and staff
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Three electrode design
PCB assembly techniques
USB processor to PC interface
External power sources
Full documentation of hardware
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Schematics
Simulation results
Assembly diagrams
List of Materials
Data/Display
Management
System
120VAC
60Hz
15A
USB
Processor
Voltage Converter
Device Under
Test
(DUT)
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Processor
◦ Firmware
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Display/Data Management System (DDMS)
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Voltage Converter
Data/Display
Management
System
120VAC
60Hz
15A
USB
Processor
Voltage Converter
Device Under
Test
(DUT)

Capture the test configuration
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Measurements to be made, ranges, etc.
Execute the test using the measurements that have been
established by the operator
Log and time stamp test results in NVRAM
Send measurement data to Display/Data Management
System (DDMS) during test
When polled by the DDMS, send the test results in CSV
format to a file on the PC
Data/Display
Management
System
120VAC
60Hz
15A
USB
Processor
Voltage Converter
Device Under
Test
(DUT)
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Test Mode
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Execute test script that was entered during Pre-Test
Display results during test
Post Processing
◦ Report generation
Data/Display
Management
System
120VAC
60Hz
15A
USB
Processor
Voltage Converter
Device Under
Test
(DUT)
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Three options are available:
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Wall Wart
USB
Battery power
Microprocessor requires 5 VDC
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Estimated 3 watts
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Develop GUI and firmware using modern
software engineering techniques
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No spaghetti code
Comment all code
Provide a software library
Document all the application software and
firmware
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Installation notes
User’s Manual
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Display/Data Management System (DDMS)
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Ardustat
◦ Arduino Development Board
◦ Daughtercard
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Capture Input Parameters
Transmit Configuration to Arduino Development
Board
Start Experiment Procedure
Export Logged Data
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Capture Configuration
Send Commands to Daughtercard
Export Measured Data
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Capture Measurements
Send Measurements to Arduino Development
Board
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Prepare four orange juice samples, one as a
control, the other three containing the
addition of exogenous ascorbic acid at
0.1,.02, and 0.3M respectively.
Prepare a working electrode using a graphite
pencil “lead”.
Prepare a reference electrode using a
standard Ag/AgCl electrode.
Prepare a counter electrode using a piece of
platinum wiring. (This will not be used for the
Two Electrode Potentiostat configuration)
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Attach the electrodes to the Potentiostat
systems.
Perform a cyclic voltammetry test taken from
200 to 900 mV, with a constant current of
550 mV.
Export the data to CSV file and graph the
results.
Analyze graphed results against Rowe’s
results using an eye inspection test.
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Two Electrode Potentiostat
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Three Electrode Potentiostat
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Although the tests show that both systems
work, the results were not as expected
Several possibilities:
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Ag/AgCl reference electrode
Relay usage
Firmware implementation(?)
Chemical procedure integrity
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Universal System
◦ Verify suggested conclusion and recommendations
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Two Electrode Potentiostat
◦ Other modes of operation
◦ Calibration settings
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Three Electrode Potentiostat
◦ Implement DDMS GUI
 Removed joystick and LCD